Drop temporaries as early as possible in $:expr case

src/macros.rs

@@ -173,9 +173,10 @@ macro_rules! anyhow {
     });
     ($err:expr $(,)?) => ({
         use $crate::private::kind::*;
-        match $err {
+        let error = match $err {
             error => (&error).anyhow_kind().new(error),
-        }
+        };
+        error
     });
     ($fmt:expr, $($arg:tt)*) => {
         $crate::Error::msg($crate::private::format!($fmt, $($arg)*))

tests/ui/temporary-value.stderr

@@ -2,7 +2,8 @@ error[E0716]: temporary value dropped while borrowed
  --> tests/ui/temporary-value.rs:4:22
   |
 4 |     let _ = anyhow!(&String::new());
-  |             ---------^^^^^^^^^^^^^-- temporary value is freed at the end of this statement
+  |             ---------^^^^^^^^^^^^^-
   |             |        |
   |             |        creates a temporary which is freed while still in use
+  |             temporary value is freed at the end of this statement
   |             argument requires that borrow lasts for `'static`